It has been taught by Yuto and Suzuki (U.S. Pat. Nos. 4,547,328 and 4,683,166) that the addition of at least 20% by weight of a 55% or greater die swell ratio (DSR) plastic to a polymer blend produces certain advantages in the making of coaxial cable. Specifically, the addition of the 55% or greater DSR polymer increases the elasticity of the melted polymer, allowing better control over the process whereby wire is coated with a foamed insulation. The teachings indicate that advantages are obtained from a high degree of foaming (expansion ratio) and a cell structure of the foamed polymer that is 50 microns or less. Small cell structures at high expansion ratios are desirable for the properties of low electrical loss (attenuation), low material usage and improved mechanical strength. It is understood by those skilled in the art that the prior art had to restrict the 55% or greater DSR material to no less than 20% of the total mixture in order to maintain aforementioned desirable cell structure, high expansion ratio, and stress crack resistance. However, in order to enhance dimensional stability and mechanical strength of the cable, the foamed insulation layer was coated with an unfoamed solid polymer layer or skin. It is known that such a layer adds complexity to the manufacturing process and increases the cost of initial capital and ongoing material usage. Additionally, the high DSR materials themselves are electrically disadvantaged, and thus adversely affect the electrical purity (dissipation factor) of the cable.